The Wide-Angle Difference
The physical differences between Canon’s EF and EF-S series lenses permit the EF-S lenses to capture a bit more of a given scene at a specific focal length.
Let’s take a look at how the "wide-angle" effect works with actual wide-angle lenses.
Figure 6 shows a photo captured with the Canon 20D using the EF-S 10-22mm f/3.5-4.5 USM lens at 20mm and f/16.
Figure 6 As always for the comparison shots, a tripod was used.
Figure 7 The same scene; same focal length; different lens.
As you can see, the difference between EF-S and EF lenses, in terms of how much of a scene is captured, is minimal when shooting with wide-angle lenses.